60 years ago: Aurora 7 & ‘double authority’

May 24, 1962: Scott Carpenter enters Aurora 7 for the second U.S. orbital flight.

***

You’re Scott Carpenter, explorer, ready to unleash your curiosity.   They’ve loaded your Mercury Atlas (MA-7) flight with experiments and tests.  You’re all for it — let’s see what a Mercury can do.  You’ve got the spirit.  You’re gonna be up there for the experience, absorb it all, the joy of flight, the mysteries of the heavens.

You’ll take on five new experiments squeezed into the same duration of John Glenn’s flight.  Just three orbits aboard your capsule, Aurora 7, to do it all.   It might be hubris, attempting so much after just one orbital flight.

You’d only taken over the flight from Deke Slayton in mid-March, then aimed for an early May launch. The launched slipped to May 17.  Still, a tight time squeeze.  Frankly, you felt a bit overwhelmed by the flight plan, your confidence taking a hit.  Then a string of small mechanical problems delays the flight by a week.  The extra days give you time to come up to speed.  Your anxiety evaporates.  Your confidence returns; you are ready to probe the secrets of space.

On the morning of May 24, 1962, a perfect countdown purrs towards its conclusion, wrapped in a primordial soup of fog, toward a planned 7 a.m., Eastern time, launch.   The ground fog mixes with the smoke of distant brush fires and the vapors of the steaming Atlas rocket.  Eleven minutes to go and . . . holding, a hold for the fog to diminish.  We wait for 44 minutes.  While the fog doesn’t completely disappear, it’s thin enough to allow tracking.  We’re counting again.  The Atlas could be dormant — you don’t hear the clattering sounds John Glenn reported and only feel the engines gimbaling into position.  Ignition, and the vehicle begins to shake.

At 7:45, through sunlit wafer of lingering mist, Aurora 7 rises.  “I feel the liftoff. The clock has started.”    

Through Max Q, maximum aerodynamic pressure, forces building.   The sky, while not black, shifts to dark blue.  BECO, Booster Engine Cutoff, the two booster engines shutdown and are jettisoned.  Shutdown was gentle, but you can feel when those engines are cut loose, and see a puff of smoke by the window.  Pitching over, parallel to the earth, picking up some side-to-side (yaw) oscillations that slowly increase, yet you don’t feel the sensation reported by John Glenn of being at the end of a springboard.  It all happens too quickly, five minutes to orbit passing in a quick tremor through the bones.   SECO, sustainer engine cutoff, 5 min. 9 sec. after liftoff.  The roar of engines replaced by . . . absolute silence.  “It’s very quiet.” 

Then bang — explosive bolts severe the clamps attaching Aurora 7 to the booster’s adapter ring. And another bang — the three small posigrade rockets fire to push the capsule from the spent booster.  You are free.

“I am weightless!”  The strongest cue that the seat and suit feel more comfortable.   

Capcom Gus Grissom radios that your orbit is good, stable.  

“Roger.  Sweet words,” you reply.

Switching from the automatic ASCS.  Manual turnaround on fly-by-wire, hoping to use less fuel than the auto system did on John Glenn’s flight.  In fly-by-wire, electronic impulses fire the jets rather than the old-fashioned mechanical linkages of the manual system.  Fly-by-wire proves very responsive.  The horizon slides into view.

You nudge into orbit attitude — heatshield forward, nose canted down 34 degrees — using just 1.6 pounds of fuel, less than half that normally expended.   “I have the booster in the center of the window now, tumbling very slowly.”  It’s silver skin very bright.  A steady stream of white gas spews out of the engine bell for three times its length, fanning out into nothingness.  

Seven minutes after launch.  “Going to ASCS now.”  Back on the automatic side of the attitude control system.  Each side, automatic and manual, has its own fuel supply.  And the fly-by-wire is a hybrid where the control stick operates the thrusters of the automatic system and uses its fuel supply.  

“ASCS seems to be holding well.”  However, after crossing the Atlantic, you radio the Canaries, “I think my attitude is not in agreement with the instruments.”  The auto system is pitching the nose lower than it should.  In fact, after the flight, data will show that the yaw horizon sensor began picking up an error during launch and was off by 20 degrees at the time you reached orbit.

You think maybe the gyroscopes just need time to lock in.  You don’t have time to worry about it now or do a complete system check, not with so much to do.  Already time to begin photography tasks that dominate the first orbit.  And, indeed, the gyro system seems to settle down.  In fact, the error in yaw will persist, varying throughout the flight, and at times appearing normal, masking it’s malfunction. 

Crossing the African coast, already falling behind the science plan.  Fumbling to load the camera with special MIT film for daylight horizon pictures, an awkward task in gloves.

“Pitching down, yawing left.”   Begin the first of a myriad of maneuvers to observe the horizon, landmarks, sunsets, stars, the sun. With so many photo and observation targets, you need to make extensive maneuvers.  And with time tight, you are impatient.  Instead of maneuvering slowly, which would save fuel, you kick the capsule around. 

Feeling hot, the heat pulse from launch still soaking through the capsule skin. The suit cooling doesn’t see to be coping.  The ground is concerned, but the heat is bearable.  You feel fine, you tell them. 

“Oh, look at that sun” setting over the Indian Ocean, 45 minutes since launch.  “Bright, bright blue horizon band as the sun gets lower. . .”

Two minutes later, ‘It’s now nearly dark, and I can’t believe where I am.’

Swinging about, nosing Aurora 7 to take it all in, the earth in moonlight.  The welcoming lights of Perth, Australia.  “Oh, dear, I’ve used too much fuel.”  Only 48 minutes into the five-hour flight.

Sunrise over Hawaii, less than an hour-and-a-half since launch.  You’re facing away from it and don’t notice them.  Until you yaw Aurora 7 around.  “I have the fireflies.”  John Glenn’s fireflies,  swirling lazily around the capsule.   “Almost like a light snowflake particle caught in an eddy.”

Approaching Baja California, fuel already down to 69 percent in the automatic system and the same in the manual loop.  Thirty-five percent of the automatic’s fuel must be reserved for re-entry.  The capcom at Guaymas, Mexico, Gordo Cooper, suggests, “Start to conserve your fuel a bit and maybe, perhaps use a little more of your manual fuel.”

*

You begin your second orbit manual control system.   

The Cape calls, ‘Aurora 7, have you deployed the balloon?’

You punch the button to release a balloon from the capsule’s nose.  Thirty  inches in diameter when inflated, it stays connected to the capsule by a 98-foot nylon line.  The balloon is painted different colors to help determine which show up best in space.   However, it doesn’t inflate properly.  Perhaps ripped, it appears about 10 inches in diameter, with a floppy Micky Mouse ears.  Can see, thought, that the orange shows up the best.

Using more fuel to watch the balloon’s motions.  They predicted it would trail the capsule, waving back and forth in uniform oscillations.  Instead, it moves randomly.  

The Canary Capcom says, “MCC [Mercury Control Center] is worried about your auto fuel and manual fuel consumption.  They recommend that you try to conserve your fuel.”

You also perform navigation tests on how well you can align the capsule’s orientation using the human eye.  You find you can gauge roll and pitch easily using the horizon as a marker.  Detecting your yaw position is much harder.  The best way is to pitch the nose down and use the ground track as a measure.

Over the Indian Ocean, the problem with the yaw gyro rears up again.  You can see that the instrument reading does not match the view out the window.  You just don’t have time to analyze it, as the ground calls for a blood pressure reading.  And you’re still working to get the suit temperature stabilized.  In orbit, time seems compressed. 

Moving out of range of the Indian Ocean Ship, 2 hours 11 minutes since launch.  Still hot, suit temperature reading 90 degrees.  Sweat roll down your face, stinging your eyes, feeling feverish, you keep fiddling with the temperature dial. “I’ll turn it up and see what happens.”  Trying every setting, taking time, not realizing the cooling system needs a half hour to adjust to each setting..  “I have gotten badly behind in the flight plan now.”  

Over Australia, second orbit.  Only 51 percent of fuel left in the automatic system, at a point where 80 percent was remaining during John Glenn’s flight.  Finally cooler, suit temperatures edging down.  

Approaching Hawaii, maneuver for pictures of sunrise.  And here come the fireflies winking on.    

“Aurora Seven, this is Capcom.  Would like for you to return the gyros to normal and see what kind of indication we have; whether or not your window view agrees with your gyros.”

“Wait one….  I have some more of the white particles in view below the capsule…  Their motion is random; they look exactly like snowflakes to me.”   

*

At the start of the third and final orbit, Cape says to let the capsule’s attitude drift, thrusters off to save fuel. You enter drifting flight,  The capsule pirouettes through a lazy arcs.   Over Africa.  “I don’t know which way I’m pointed and don’t particularly care.”   You don’t find the drifting flight disorienting.  On John Glenn’s flight, they wanted to keep in retro attitude most of the time, concerned the astronaut might lose positional awareness.  As the capsule’s nose swings towards the Earth, you feel as if you could be coming in from a distant planet.  For a moment, you become the interstellar traveler.  You drift along for more than an hour — thats more than half of the final orbit.

Final sunset over the Indian Ocean.  “It’s almost like a very brilliant rainbow.” 

Twenty-two minutes until retrofire, you start stowing equipment, but always the explorer, the observer, you are distracted.  “There’s the moon . . .looks no different than it does on Earth.’  Sunrise nine minutes later.

  “Ahh, beautiful lighted fireflies…”

Reaching for a light meter to measure their brightness, you accidentally rap the hatch.  A shower of fireflies comes off the capsule.  They must be frost on the capsule’s skin.  You test the hypothesis, rapping on the walls.  A shower of them appear.  You need more time to investigate the exact source.  But only 11 minutes from retrofire.   You risk falling behind on stowing equipment and preparing for vital retrofire.

Slicing into range of Hawaii, still yawing the capsule about, exploring the firefly phenomenon.    The capcom urges, “Aurora 7, can we get on with the checklist?” 

Just before passing out of Hawaii coverage, engage the ASCS automatic system to swing the capsule into retrofire attitude.    “Wait a minute, I have a problem in. . . I have an ASCS problem here.” 

The automatic system isn’t holding the correct attitude.  “I think I’m going to have to go to fly-by-wire and use the window and the scope.  ASCS is bad.”

Just 30 seconds to retrofire.

Rushing now to swing into position, gunning the capsule into retroattitude.  And you fail to notice that in switching control modes, you’ve left both the manual and automatic systems engaged, which means precious fuel is draining from both systems.  It’s called “double authority,” and could cost you your life.  You’ll burn fuel from both tanks for about four minutes . . .

Three, two, one:  retrofire time . . . nothing happens.  Because you are in manual control, the retros won’t fire automatically.  You punch off manual retrofire.  They fire three seconds late, every missed second equating to five miles off the landing target.  

Worse, as the retros fire, off in yaw, the capsule swinging to the side by 24, 25 degrees, the kick of the retros spewing to the side, reduced in effectiveness, which will add a 174 miles to the overshoot.  And to top it all off, the solid-fueled retros produced 3 percent less thrust than designed, adding another 59 miles to the overshoot.  Instead of  the illusion John Glenn reported of being tossed backwards, you only feel as if the capsule comes to a gentle stop.

Allowing the capsule’s attitude to drift as it passes over the United States.  Using every last moment to explore, observing, “Okay.  I can make out very, very small farm land, pasture land below: I see individual fields, rivers, lakes, roads, I think.”  You can even pick out a dirt road and believe that if a truck had been on it, it would have been visible.  You are calm, almost detached.

Over the Cape, telling the ground, “It’s going to be real tight on fuel.” 

In radio blackout now.  You speak into the capsule’s recorder.   “I hope I have enough fuel.  I get the orange glow at this time.”

You ride out the fireball, using the last fuel.  In the atmosphere, the capsule sways violently, swinging through an arc of 270 degrees.  Sunlight slicing the window in pendulum strokes.  “Oww–It’s coming like–it’s really going over.” 

If the capsule flips over, the parachutes could foul.  In an attempt to stabilize it, you fire the drogue chute from the wobbling nose of Aurora 7 at 25,000 ft., rather than waiting until the planned 21,000 ft.

The small chute steadies the capsule.  Descending beyond communications range.  At 10,000 ft. the main chute should deploy.  “The main chute is out . . . I see a perfect chute. . . . Does anybody read Aurora 7?”

You can hear Gus Grissom, but he can’t hear you.  He says, “You’re landing point is 200 miles long.  We will jump the Air Rescue people to you.”

Splashdown in the Atlantic proves gentler that you expect.  After a flight of 4 hrs. 56 min., you’re down, 135 mi. northeast of Puerto Rico.

Hot inside the capsule and worried about water possibly leaking in (it’s listing to one side), you exit, not by jettisoning the side hatch, which would sink Aurora 7, but by a more taxing route.  you squeeze out of it’s neck, like a genie out of a bottle, which entails swinging the instrument panel to the side, unbolting a bulkhead, opening a narrow passage through the capsule’s neck.  You push out a life raft ahead of you.  It inflates — upside down, of course.

Finally you settle into the raft and wait, feeling like a million bucks, enjoying the serenity of calm seas, communing with a black fish that swims along side.  It’s a wonderful moment, which like the flight doesn’t last long enough.  You have no way of  knowing that to the public, you am missing, lost, perhaps dead.

After 36 minutes, your period of quiet musing ends.  A Navy Lockheed P2V patrol plane spots you.  And soon other rescue craft follow.

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